public class Solution {
    public boolean hasPathSum(TreeNode root, int targetSum) {
        if(root == null){
            return false;
        }
        targetSum -= root.val;

        if(root.left == null && root.right == null){
            return targetSum == 0;
        }
        if(root.left != null){
            if(hasPathSum(root.left, targetSum)){
                return true;
            }
        }
        if(root.right != null){
            if(hasPathSum(root.right, targetSum)){
                return true;
            }
        }
        return false;
    }
}

class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;

    TreeNode() {
    }

    TreeNode(int val) {
        this.val = val;
    }

    TreeNode(int val, TreeNode left, TreeNode right) {
        this.val = val;
        this.left = left;
        this.right = right;
    }
}